Mary Lou Retton: Ignore your critics, do what you love

When Mary Lou Retton started in gymnastics, there weren't very many women in the sport who looked like her.

"Back in my era, gymnasts were pixies, slender, very graceful little butterflies ... I wasn't," the 48-year-old former Olympian told CNBC. "I wasn't a pretty, little gymnast. I was a very powerful, explosive gymnast."

At the 1984 Olympics, Retton proved her critics wrong when she became the first American woman to win an individual all-around gold medal in the sport.

That year she took home five medals. She was subsequently named Sports Illustrated's Sportswoman of the Year.

Suzanne Vlamis | AP

In this Aug. 3, 1984, file photo, Mary Lou Retton, of the United States, performs on the balance beam during the women's gymnastics individual all-around finals at the XXIII Summer Olympic Games in Los Angeles.

For most of her life, people told her that she didn't have the "right body" for a gymnast, Retton said.

"When people see us standing on the podium and the medal stand with gold medals draped around your neck ... that's just the pinnacle of our success, but all of us, I'm sure — I know I did — have a story of struggle, a story of overcoming adversity to actually get there," she said.

"Well, I've always been different. I don't conform and here I am. I'm proud of that fact, that those walls have come down," she said.